Certain materials such as ceramics, glass, nickel super-alloy, etc., are difficult to machine. The efficiency and effectiveness of machining operations involving such materials can be significantly improved by heating a cutting zone of the workpiece to a relatively high temperature, near the softening temperature of the material, to thereby reduce the flow stress in the material, prior to machining the finished part from the workpiece.
In order to effectively and efficiently machine the workpiece, without causing damage to a cutting tool through overheating of the cutting tool, one particular type of laser assisted machining (LAM) utilizes one or more lasers focused on a small area of the workpiece immediately ahead of the cutting tool in the cutting path of the cutting tool. Such LAM processes, utilizing one or more lasers, are illustrated in U.S. Pat. No. 4,229,640 to Longo; U.S. Pat. No. 4,925,523 to Braren et al.; U.S. Pat. No. 6,393,687 to Friedrich; U.S. Pat. No. 7,002,100 to Wu et al.; and, U.S. Pat. No. 7,257,879 to Jancsó. Such a prior approach to laser assisted machining approach is also disclosed in published U.S. Patent Application No. 2007/0062920 A1 to Shin.
Prior approaches to LAM have only been capable of efficiently and effectively producing very simple parts from workpieces having a simple shape, however, using very rudimentary machining techniques such as turning or single axis milling. The use of lasers in a conventional machining process, together with the necessity for monitoring the amount of heat and the temperature being beamed on to the workpiece during machining operations has led to unique challenges in utilizing laser assisted machinery in a broader fashion.
It is desirable to provide the advantages of laser assisted machining in more complicated machining operations, and for workpieces and final parts having more complexity than have been producible by prior approaches to LAM.